pregestational diabetes

So I just received my results from my one hour glucose test and they were elevated. My dr wants me to start a fast/diet and come in for 3 hour testing but my emotions are getting the best of me.. this is my 3rd child and I’ve never failed the test before and now my mind is spinning thinking of all the wrong things. Can someone who has pregestational diabetes comment and tell me how the pregnancy went for you or someone who failed the first test but passed the second.. I just need reassurance that everything will be fine...😞😞😞😞😞